1. Field of the Invention
The present invention relates to a seismic isolation system for a crane, which prevents derailment and the like of a large crane caused by an earthquake.
2. Description of Related Art
A xe2x80x9cOverhead Traveling Cranexe2x80x9d disclosed in Japanese Patent Publication No. 63-356 (No. 356/1988) is well known as a crane equipped with a seismic isolation system.
This xe2x80x9cOverhead Traveling Cranexe2x80x9d is, as shown in FIGS. 24 and 25, configured so that horizontal shafts 152 are mounted on saddles 151 on both sides of a narrow girder-shaped crane body 150, a track 154 having two traveling wheels 153 which travel on a rail 157 is provided on the horizontal shafts 152 so as to be slidable, and there is provided a vibration damping mechanism consisting of compression springs 155 and dampers 156, which are disposed between the opposed faces of the inside face of the saddle 151 and the track 154 so as to be parallel with the horizontal shafts 152.
On the crane of this type having the girder-shaped crane body 150, if an earthquake occurs, the crane body 150 is mainly subjected to only an excitation force perpendicular to the crane traveling direction as a dangerous external force, and the excitation force in this direction is damped by the action of the compression springs 155 and the dampers 156 to prevent the wheels from being damaged or derailed.
On a large container crane, an unloader, and the like provided on the ground, a crane body 1 is generally formed into a portal type as shown in FIGS. 17 and 18. These figures show a general construction of a container crane. This portal crane body 1 has traveling means 2 at four corners.
The traveling crane having such a portal crane body is subjected to a transverse excitation force R perpendicular to the travel direction, a transverse overturning moment M, a torsional load S (rotary load) from the travel direction to the right and left, and an impulsive axial load A by vibrations at the time of an earthquake.
Also, on the traveling crane having a large portal crane body, the height of the position of the center of gravity is very high, and therefore the natural period is long as compared with the overhead traveling crane, so that the transverse displacement of the portal crane body also increases. Therefore, even if the conventional vibration damping mechanism shown in FIG. 25 is applied to the portal crane body, a stroke necessary for damping the transverse excitation force R cannot be provided, and also damping action against the overturning moment M and the torsional load S cannot be provided.
The present invention has been made in view of the above situation, and accordingly an object thereof is to provide a seismic isolation system for a crane, which is effective even for a traveling crane having a portal crane body.
To achieve the above object, the present invention provides a seismic isolation system for a crane, provided between a crane body and traveling means having a plurality of wheels for running the crane body along a rail, comprising: a connecting mechanism which allows relative movement of the crane body and the traveling means while the crane body and the traveling means are connected to each other when an earthquake occurs; a restraining mechanism which keeps a steady relative positional relationship between the crane body and the traveling means at the normal time and allows a relative movement of the crane body and the traveling means when the relationship is broken off by a seismic force; energy absorbing means for restraining an increase in relative movement of the crane body and the traveling means caused by the occurrence of an earthquake; and a restoring mechanism for restoring the positional relationship between the crane body and the traveling means to the steady relationship.
In the above-described seismic isolation system for a crane in accordance with the present invention, the steady positional relationship between the crane body and the traveling means is kept by the restraining mechanism at the normal time. When an earthquake occurs, however, the traveling means is displaced transversely, and the crane body attempts to remain at the original position by the inertia force, so that the restraining mechanism is released by the seismic force. Therefore, a relative movement of the crane body and the traveling means occurs, and the energy caused by the relative movement is absorbed by the energy absorbing means. The relative movement of the crane body and the traveling means is relaxed properly by a damper mounted between the crane body and the traveling means. Thus, the seismic isolation function is fulfilled safely and properly.
Also, the present invention provides a seismic isolation system for a crane, provided between a crane body and traveling means having a plurality of wheels for running the crane body along a rail, comprising a swing bearing ring consisting of a lower ring installed horizontally on the side of the traveling means and an upper ring engaging concentrically with the lower ring so as to be rotatable relatively, and further comprising a vertical shaft supporting swing bearing provided at an eccentric position on the upper ring of the swing bearing ring; a crane load supporting block having a lower vertical shaft supported on the swing bearing; saddles installed at the lower part of the crane body so as to pivotally support the block by using a horizontal transverse shaft; a horizontal lever whose proximal end is pivotally supported on the upper ring of the swing bearing ring through the horizontal transverse shaft; and a horizontal lever swing restoring mechanism which automatically restores the horizontal lever to the neutral position while supporting the distal end of the horizontal lever so as to be rotatable around the vertical centerline of the swing bearing ring.
In the above-described seismic isolation system for a crane in accordance with the present invention, the load of the crane body is transmitted from the saddles installed on the crane body to the traveling means through the crane load supporting block, the swing bearing, and the swing bearing ring.
An axial load, a overturning moment load, and a radial load applied to the crane body by an earthquake during the operation of the crane are supported by the swing bearing ring and the swing bearing on the traveling means.
Also, an excitation force applied in the radial direction perpendicular to the travel direction of the traveling means acts on the lower ring of the swing bearing ring on the traveling means so as to turn the swing bearing, which is erected at an eccentric position from the center of the swing bearing ring, around the vertical centerline of the swing bearing ring together with the horizontal lever. This turning force is automatically restrained by the horizontal lever swing restoring mechanism provided between the horizontal lever and the traveling means, whereby a damping operation against the excitation force is performed.
In the seismic isolation system for a crane in accordance with the present invention, the horizontal lever swing restoring mechanism comprises a roller which is provided at the distal end of the horizontal lever so as to be rotatable freely along the swing direction, and a guide rail provided on the traveling means so as to be inclined downward toward the middle position of the rail, which is the neutral position.
When the guide rail for guiding the roller (or a wheel) at the distal end of the horizontal lever mounted on the swing bearing ring is provided so as to be inclined downward from both sides thereof toward the rail middle position, which is the neutral position, as described above, the operation in which the horizontal lever having been swung by seismic vibrations is automatically restored to the neutral position is performed properly when the roller having been pushed against the guide rail by the gravity of the crane body is automatically restored to the rail middle position. Also, when the horizontal lever is swung by seismic vibrations, the roller climbs the inclined face of the guide rail, so that the swinging motion of the horizontal lever is restrained.
Also, in the seismic isolation system for a crane in accordance with the present invention, the horizontal lever swing restoring mechanism is composed of a laminated rubber mounted between the lower face of the horizontal lever and the upper face of the traveling means.
When the horizontal lever swing restoring mechanism is composed of the laminated rubber mounted between the lower face of the horizontal lever and the upper face of the traveling means as described above, the swinging motion of the horizontal lever is properly restrained by the spring effect and damping effect of the laminated rubber itself, and the operation in which the horizontal lever is automatically restored to the swing amount zero position (neutral position) is performed properly.
Further, in the seismic isolation system for a crane in accordance with the present invention, the horizontal lever swing restoring mechanism comprises a coil spring mounted between the lower face of the horizontal lever and the upper face of the traveling means, and an antifriction guide member interposed between the horizontal lever and the traveling means so as to guide the distal end of the horizontal lever in the swing direction of the lever along the upper face of the traveling means.
When the horizontal lever swing restoring mechanism is composed of the coil spring mounted between the lower face of the horizontal lever and the upper face of the traveling means as described above, as well, the swinging motion of the horizontal lever is elastically restrained properly by the coil spring at the time of an earthquake along with the operation of the antifriction guide member such as a roller for guiding the horizontal lever in the lever swing direction along the upper face of the traveling means. Also, the operation in which the horizontal lever having been swung by seismic vibrations is automatically restored to the neutral position is performed properly by the automatic restoring function of the coil spring.
Also, in the seismic isolation system for a crane in accordance with the present invention, braking means for braking the swinging motion of the horizontal lever is provided on the traveling means.
When the braking means for braking the swinging motion of the horizontal lever is provided as described above, an active damping operation is performed when an earthquake occurs.
Further, in the seismic isolation system for a crane in accordance with the present invention, a damper (hydraulic vibration exciter) for restraining the swinging motion of the horizontal lever is mounted between the traveling means and the horizontal lever. Therefore, the operation in which the swinging motion of the horizontal lever is restrained is performed sufficiently even by the use of such a damper, whereby the operation for actively damping the crane body can be performed when seismic vibrations occur.
Also, the present invention provides a seismic isolation system for a crane, provided between a crane body and traveling means having a plurality of wheels for running the crane body along a rail, comprising: a laminated rubber mounted between the lower face of the crane body and the central portion of the traveling means; and transverse slide mechanisms mounted between the lower face of the crane body and the upper face of the traveling means at longitudinally symmetrical positions with respect to the laminated rubber.
In the above-described seismic isolation system for a crane in accordance with the present invention, when a transverse excitation force is applied to the crane body by an earthquake, the crane body slides transversely while supporting a bending moment by using the transverse slide mechanisms. At this time, the sliding force between the crane body and the traveling means is absorbed by the deflection of the laminated rubber, and the crane body is automatically restored to the normal position with respect to the traveling means by the restoring force of the laminated rubber.
In the seismic isolation system for a crane in accordance with the present invention, a damper for restraining the transverse slide amount is mounted between the crane body and the traveling means. Therefore, the transverse movement of the crane body is restrained properly when seismic vibrations occur, along with the operation in which the transverse slide amount is restrained by such a damper.
Also, in the seismic isolation system for a crane in accordance with the present invention, there are provided a vibration detecting sensor for detecting vibrations of the crane body and the traveling means when an earthquake occurs, a vibration control section which sends a control signal for restraining the vibrations of the crane body in response to a detection signal sent from the sensor, and driving means which operates between the crane body and the traveling means so as to restrain the vibrations of the crane body according to the control signal sent from the vibration control section.
In the above-described seismic isolation system for a crane in accordance with the present invention, vibrations of the traveling means are detected by the vibration detecting sensor and taken in the vibration control section when seismic vibrations occur, and the driving means is controlled by the control signal sent from the control section so that the crane body is isolated from the vibrations of the traveling means. Therefore, the transverse vibrations of the crane body caused by an earthquake are restrained actively.
Further, the present invention provides a seismic isolation system for a crane, provided between a crane body and traveling means having a plurality of wheels for running the crane body along a rail, wherein the lower part of the crane body and the upper center of the traveling means are connected to each other by a universal joint mechanism, and vibration damping mechanisms, which connect the crane body to the traveling means, are interposed at positions on both sides of the universal joint mechanism.
In the above-described seismic isolation system for a crane in accordance with the present invention, the vibration damping mechanisms located on both sides of the universal joint mechanism are balanced mutually so as to keep the universal joint block vertical at the normal time. In this state, the weight of the crane body is transmitted as an axial load to the traveling means through the universal joint mechanism.
Also, the axial load, the overturning load, and the radial load applied to the crane body when seismic vibrations occur are also transmitted similarly to between the traveling means and the crane body through the universal joint mechanism.
A transverse excitation force applied to the crane body perpendicularly to the travel direction by seismic vibrations is absorbed as vibrations with a long vibration period by the turning motion of the crane body around the longitudinal horizontal axis in the universal joint mechanism.
Also, when the vibration damping mechanisms, which connect the crane body to the traveling means, are interposed at longitudinally symmetrical positions with respect to the universal joint mechanism, a longitudinal excitation force applied to the crane body by seismic vibrations is also damped properly.
Further, when the universal joint mechanism comprises saddles projecting downward from the lower part of the crane body, a universal joint block whose upper part is pivotally mounted to the saddles via a shaft in the travel direction, and a lower pivotally mounting portion which pivotally mounts the lower part of the universal joint block to a bearing on the traveling means via a horizontal transverse shaft, the construction of the universal joint mechanism is compact and has a high strength, and the arrangement thereof is effected properly.
Further, the present invention provides a seismic isolation system for a crane, provided between a crane body and traveling means having a plurality of wheels for running the crane body along a rail, comprising a laminated rubber mounted between the lower face of the crane body and the central portion of the traveling means; and turnover preventive restraining members interposed between the lower face of the crane body and the upper face of the traveling means at positions on both sides of the laminated rubber.
In the above-described seismic isolation system for a crane in accordance with the present invention, a transverse relative displacement produced between the crane body and the traveling means by an earthquake is absorbed by the spring element and the friction damping due to the deformation of the laminated rubber. At the same time, the overturning moment load applied along with the transverse radial load is supported by the resisting force of the turnover preventive restraining members on both sides, and the restoring operation to the deflection zero position is performed properly by the restoring force of the laminated rubber.
Also, in the seismic isolation system for a crane in accordance with the present invention, a trigger mechanism for restraining the horizontal relative displacement between the crane body and the traveling means is provided between the crane body and the traveling means, and when the trigger mechanism is subjected to an excitation force having a given value or larger by an earthquake, the restraint of relative displacement is released.
In the above-described seismic isolation system for a crane, when an excitation force exceeding the given value is applied to the crane by an earthquake, the trigger mechanism is released, and the seismic isolation function is fulfilled by the laminated rubber and the turnover preventive restraining members on both sides of the laminated rubber. In the normal state in which no earthquake occurs, the crane body and the traveling means are connected to each other integrally by the trigger mechanism, so that the rigidity of the whole crane is maintained.
Also, the present invention provides a seismic isolation system for a crane, provided between a crane body and traveling means having a plurality of wheels for running the crane body along a rail, comprising inclined guide means which guides the relative movement of the crane body when the traveling means is displaced transversely by a seismic force when an earthquake occurs, and additionally provides a restoring function, the inclined guide means comprising a first swing bearing ring consisting of a lower ring mounted on the traveling means in an inclined state and an upper ring engaging concentrically with the lower ring so as to be rotatable relatively; an inclined beam provided integrally with the upper ring of the first swing bearing ring; a second swing bearing ring consisting of a lower ring mounted on the upper face of the inclined beam so as to have the rotation centerline at a position shifted horizontally from the rotation centerline of the first swing bearing ring and an upper ring engaging concentrically with the lower ring so as to be rotatable relatively; and a crane body connecting portion for connecting the upper ring of the second swing bearing ring to the lower part of the crane body.
In the above-described seismic isolation system for a crane in accordance with the present invention, the load of the crane body is supported via the first swing bearing on the side of the traveling means, the inclined beam at the middle part, and the second swing bearing ring on the side of the crane body, and further via the crane body connecting portion.
When the traveling means moves in the transverse direction together with the rail at the time of the occurrence of earthquake, since the first swing bearing ring and the second swing bearing ring have the mutually shifted respective rotation centerlines, the crane body attempts to remain by the inertia force and shifts transversely relative to the traveling means. Accordingly, the inclined beam is swung and pushes up the crane body in cooperation with the second swing bearing ring on the beam. Thus, the crane body mainly moves vertically due to the reciprocating transverse movement of the traveling means caused by an earthquake, so that the period of the crane body is made long, and the seismic isolation function is fulfilled.
Further, in the seismic isolation system for a crane in accordance with the present invention, the crane body connecting portion comprises a hinge pin type connecting member and a hydraulic cylinder each of which is mounted between the upper ring of the second swing bearing ring and the crane body.
When the upper ring of the second swing bearing ring and the crane body are connected to each other by the hinge pin type connecting member and the hydraulic cylinder so that the inclination is adjustable as described above, the crane body can be kept horizontal by the extending/contracting adjustment of the hydraulic cylinder according to the face angle of the inclined beam, and the relative relationship of the crane body with the second swing bearing ring can be fixed properly.
Also, in the seismic isolation system for a crane in accordance with the present invention, a restraining mechanism, which restrains the rotation of the inclined beam at the normal time and allows the rotation of the inclined beam when the restraint is released by the seismic force at the time of the occurrence of an earthquake, is mounted between the inclined beam and the traveling means, and a damper for restraining the rotation of the inclined beam is mounted between the inclined beam and the traveling means.
When the restraining mechanism such as a shear pin or a brake is provided between the inclined beam and the traveling means so that the restraining mechanism is released only when an earthquake occurs as described above, the inclined beam is fixed at the normal time, so that a stable operation is performed as in the case of the conventional crane equipment. When the restraining mechanism is released by the seismic force and the inclined beam is turned reciprocatively, since the damper is provided to restrain the turning of the inclined beam, the seismic energy is absorbed while the relative movement of the crane body and the traveling means is relaxed properly.
Further, the present invention provides a seismic isolation system for a crane, provided between a crane body and traveling means having a plurality of wheels for running the crane body along a rail, wherein a spring mechanism is provided between the crane body and the traveling means to elastically keep a steady positional relationship between the crane body and the traveling means; a movable connecting mechanism which connects the crane body to the traveling means while allowing the relative displacement of the crane body, which attempts to remain at the original position by the inertia force acting on the crane body when the traveling means vibrates transversely due to the occurrence of an earthquake, with respect to the traveling means and a damper for restraining a relative displacement between the crane body and the traveling means, which is effected via the spring mechanism, are interposed between the crane body and the traveling means, and the movable connecting mechanism comprises a fist swing bearing ring consisting of a lower ring mounted horizontally on the side of the traveling means and an upper ring engaging concentrically with the lower ring so as to be rotatable relatively, a horizontal beam provided integrally with the upper ring of the first swing bearing ring, a second swing bearing ring consisting of a lower ring mounted on the upper face of the horizontal beam so as to have the rotation centerline at a position shifted horizontally from the rotation centerline of the first swing bearing ring and an upper ring engaging concentrically with the lower ring so as to be rotatable relatively, and a crane body connecting portion for connecting the upper ring of the second swing bearing ring to the lower part of the crane body.
In the above-described seismic isolation system for a crane in accordance with the present invention, in the movable connecting mechanism for connecting the crane body to the traveling means, the horizontal beam is provided in place of the inclined beam. Therefore, the relative movement caused between the traveling means and the crane body by the cooperative action of the horizontal beam and the first and second swing bearing rings below and above the horizontal beam when an earthquake occurs is effected only in the horizontal plane. The steady positional relationship between the traveling means and the crane body is kept by the spring mechanism, and the relative movement of the crane body and the traveling means, which is effected via the spring mechanism when an earthquake occurs, is relaxed by the damper. Thus, the seismic isolation function for the crane body is fulfilled properly while the seismic energy is absorbed.
In this case as well, the load of the crane body is supported without a difficulty through the first swing bearing ring on the side of the traveling means, the horizontal beam at the middle part, and the second swing bearing ring on the side of the crane body, and further through the crane body connecting portion.
Further, in the seismic isolation system for a crane in accordance with the present invention, a restraining mechanism, which restrains the rotation of the horizontal beam at the normal time and allows the rotation of the horizontal beam when the restraint is released by the seismic force at the time of the occurrence of an earthquake, is mounted between the horizontal beam and the traveling means.
When the restraining mechanism such as a shear pin or a brake is provided between the horizontal beam and the traveling means so that the restraining mechanism is released only when an earthquake occurs as described above, the horizontal beam is fixed at the normal time, so that a stable operation is performed as in the case of the conventional crane equipment.
As described in detail above, the seismic isolation system for a crane in accordance with the present invention achieves the following effects:
(1) The steady positional relationship between the crane body and the traveling means are held by the restraining mechanism at the normal time. When an earthquake occurs, the traveling means is displaced transversely, and the crane body attempts to remain by the inertia force. When the restraining mechanism is released by the seismic force, a relative movement of the crane body and the traveling means takes place, and the energy due to the relative movement is absorbed by the energy absorbing means. the relative movement (vibration) of the crane body and the traveling means is properly relaxed by the damper mounted between the crane body and the traveling means. Thus, the seismic isolation function is fulfilled safely and properly. (Claim 1)
(2) The load of the crane body is transmitted from the saddles installed to the crane body to the traveling means through the crane load supporting block, the swing bearing, and the swing bearing ring. An axial load, overturning load, and radial load applied to the crane body by seismic vibrations during the operation of the crane are supported by the swing bearing ring and the swing bearing on the traveling means. An excitation force applied in the radial direction perpendicular to the travel direction of the traveling means acts on the lower ring of the swing bearing ring on the traveling means so as to turn the swing bearing, which is erected at an eccentric position from the center of the swing bearing ring, around the vertical centerline of the swing bearing ring together with the horizontal lever. This turning force is automatically restrained by the horizontal lever swing restoring mechanism provided between the horizontal lever and the traveling means, whereby a damping operation against the excitation force is performed. (Claim 2)
(3) When the guide rail for guiding the roller (or the wheel) at the distal end of the horizontal lever mounted on the swing bearing ring is provided so as to be inclined downward from both sides thereof toward the rail middle position, which is the neutral position, the operation in which the horizontal lever having been swung by seismic vibrations is automatically restored to the neutral position is performed properly when the roller having been pushed against the guide rail by the gravity of the crane body is automatically restored to the rail middle position. Also, when the horizontal lever is swung by seismic vibrations, the roller climbs the inclined face of the guide rail, so that the swinging motion of the horizontal lever is restrained. (Claim 3)
(4) When the horizontal lever swing restoring mechanism is composed of the laminated rubber mounted between the lower face of the horizontal lever and the upper face of the traveling means, the swinging motion of the horizontal lever is properly restrained by the spring effect and damping effect of the laminated rubber itself, and the operation in which the horizontal lever is automatically restored to the swing amount zero position (neutral position) is performed properly. (Claim 4)
(5) When the horizontal lever swing restoring mechanism is composed of the coil spring mounted between the lower face of the horizontal lever and the upper face of the traveling means, as well, the swinging motion of the horizontal lever is elastically restrained properly by the coil spring at the time of an earthquake along with the operation of the antifriction guide member such as a roller for guiding the horizontal lever in the lever swing direction along the upper face of the traveling means. Also, the operation in which the horizontal lever having been swung by seismic vibrations is automatically restored to the neutral position is performed properly by the automatic restoring function of the coil spring. (Claim 5)
(6) When the braking means for braking the swinging motion of the horizontal lever is provided, an active damping operation is performed when an earthquake occurs. (Claim 6)
(7) The operation in which the swinging motion of the horizontal lever is restrained is performed sufficiently even by the use of such a damper (vibration exciter), whereby the operation for actively damping the crane body can be performed when seismic vibrations occur. (Claim 7)
(8) When there are provided the laminated rubber mounted between the lower face of the crane body and the central portion of the traveling means and the transverse slide mechanisms mounted between the lower face of the crane body and the upper face of the traveling means at longitudinally symmetrical positions with respect to the laminated rubber, the crane body slides transversely while supporting a bending moment by using the transverse slide mechanisms when a transverse excitation force is applied to the crane body by an earthquake. At this time, the sliding force between the crane body and the traveling means is absorbed by the deflection of the laminated rubber, and the crane body is automatically restored to the normal position with respect to the traveling means by the restoring force of the laminated rubber. (Claim 8)
(9) When the oil damper for restraining the transverse slide amount is mounted between the crane body and the traveling means, the transverse movement of the crane body is restrained properly when seismic vibrations occur, along with the operation in which the transverse slide amount is restrained by the oil damper. (Claim 9)
(10) Vibrations of the crane body with respect to the traveling means are detected by the vibration detecting sensor and taken in the vibration control section when seismic vibrations occur, and the driving means is controlled by the control signal sent from the control section so that the crane body is isolated from the vibrations of the traveling means. Thereby, the transverse vibrations of the crane body caused by an earthquake are damped actively. (Claim 10)
(11) When the lower part of the crane body and the upper center of the traveling means are connected to each other by the universal joint mechanism, and the vibration damping mechanisms, which connect the crane body to the traveling means, are interposed at positions on both sides of the universal joint mechanism, a transverse excitation force applied to the crane body perpendicularly to the travel direction by seismic vibrations is absorbed as vibrations with a long vibration period by the turning motion of the crane body around the longitudinal horizontal axis in the universal joint mechanism. (Claim 11)
(12) When the vibration damping mechanisms, which connect the crane body to the traveling means, are interposed at longitudinally symmetrical positions with respect to the universal joint mechanism, a longitudinal excitation force applied to the crane body by seismic vibrations is also damped properly. (Claim 12)
(13) When the universal joint mechanism comprises saddles projecting downward from the lower part of the crane body, a universal joint block whose upper part is pivotally mounted to the saddles via a shaft in the travel direction, and a lower pivotally mounting portion which pivotally mounts the lower part of the universal joint block to a bearing on the traveling means via a horizontal transverse shaft, the construction of the universal joint mechanism is compact and has a high strength, and the arrangement thereof is effected properly. (Claim 13)
(14) When there are provided the laminated rubber mounted between the lower face of the crane body and the central portion of the traveling means and the turnover preventive restraining members interposed between the lower face of the crane body and the upper face of the traveling means at positions on both sides of the laminated rubber, a transverse relative displacement produced between the crane body and the traveling means by an earthquake is absorbed by the spring effect and the friction damping due to the deformation of the laminated rubber. At the same time, the overturning moment load applied along with the transverse radial load is supported by the resisting force of the turnover preventive restraining members on both sides, and the restoring operation to the deflection zero position is performed properly by the restoring force of the laminated rubber. (Claim 14)
(15) When the laminated rubber and the turnover preventive restraint members on both sides of the laminated rubber are provided, and also the trigger mechanism is provided between the crane body and the traveling means, the trigger mechanism is released when an excitation force exceeding the given value is applied to the crane by an earthquake, and the seismic isolation function is fulfilled by the laminated rubber and the turnover preventive restraining members on both sides of the laminated rubber. In the normal state in which no earthquake occurs, the crane body and the traveling means are connected to each other integrally by the trigger mechanism, so that the rigidity of the whole crane is maintained. (Claim 15)
(16) The load of the crane body is supported via the first swing bearing on the side of the traveling means, the inclined beam at the middle part, and the second swing bearing ring on the side of the crane body, and further via the crane body connecting portion. When the traveling means moves in the transverse direction together with the rail at the time of the occurrence of earthquake, since the first swing bearing ring and the second swing bearing ring have the mutually shifted respective rotation centerlines, the crane body attempts to remain by the inertia force and shifts transversely relative to the traveling means. Accordingly, the inclined beam is swung and pushes up the crane body in cooperation with the second swing bearing ring on the beam. Thus, the crane body mainly moves vertically due to the reciprocating transverse movement of the traveling means caused by an earthquake, so that the period of the crane body is made long, and the seismic isolation function is fulfilled. (Claim 16)
(17) When the upper ring of the second swing bearing ring and the crane body are connected to each other by the hinge pin type connecting member and the hydraulic cylinder so that the inclination is adjustable, the crane body can be kept horizontal by the extending/contracting adjustment of the hydraulic cylinder according to the face angle of the inclined beam, and the relative relationship of the crane body with the second swing bearing ring can be fixed properly. (Claim 17)
(18) When the restraining mechanism such as a shear pin or a brake is provided between the inclined beam and the traveling means so that the restraining mechanism is released only when an earthquake occurs, the inclined beam is fixed at the normal time, so that a stable operation is performed as in the case of the conventional crane equipment. When the restraining mechanism is released by the seismic force and the inclined beam is turned reciprocatively, since the oil damper is provided to restrain the turning of the inclined beam, the seismic energy is absorbed while the relative movement of the crane body and the traveling means is relaxed properly. (Claim 18)
(19) In the movable connecting mechanism for connecting the crane body to the traveling means, the horizontal beam is provided in place of the inclined beam. Therefore, the relative movement caused between the traveling means and the crane body by the cooperative action of the horizontal beam and the first and second swing bearing rings below and above the horizontal beam when an earthquake occurs is effected only in the horizontal plane. The steady positional relationship between the traveling means and the crane body is kept by the spring mechanism, and the relative movement of the crane body and the traveling means, which is effected via the spring mechanism when an earthquake occurs, is relaxed by the oil damper. Thus, the seismic isolation function for the crane body is fulfilled properly while the seismic energy is absorbed. In this case as well, the load of the crane body is supported without a difficulty through the first swing bearing ring on the side of the traveling means, the horizontal beam at the middle part, and the second swing bearing ring on the side of the crane body, and further through the crane body connecting portion. (Claim 19)
(20) When the restraining mechanism such as a shear pin or a brake is provided between the horizontal beam and the traveling means so that the restraining mechanism is released only when an earthquake occurs, the horizontal beam is fixed at the normal time, so that a stable operation is performed as in the case of the conventional crane equipment. (Claim 20)